(1) Field of the Invention
The present invention relates to a communication device, and more particularly, to a communication device for communicating with a remote device by using one of a plurality of paths.
(2) Description of the Related Art
In TCP/IP (Transmission Control Protocol/Internet Protocol) communications, for example, basically an IP packet reaches a destination communication device via a plurality of routers, and one path is usually selected from a plurality of paths to carry out communication.
As a method of selecting one path from among multiple paths, a protocol called RIP (Routing Information Protocol) has been in use, for example. In RIP, each router stores the addresses of neighboring devices and hop counts, and sends out a received IP packet to a path with the smallest hop count, thereby selecting an optimum path.
According to RIP, however, a path is selected by looking up only the hop counts, and accordingly, it is not possible to make path selection reflecting congestion conditions.
Also, in cases where a certain device on a network has developed a fault, it is necessary that routing should be changed. Conventionally, however, information indicative of such fault is propagated by means of communications between individual devices, and a problem therefore arises in that considerable time is required before the routing information converges.